System and method for restoring kinetic properties of resin

ABSTRACT

A system and method configured to restore ion exchange kinetic properties and purify resin is described. Degraded ion exchange kinetic properties of anion resin will eventually result in impurity slippage through resin charges. This system and method employs an acid catalyst in combination with sulfite cleaning solution to remove organic material and to protonate iron oxides for deconstruction and removal from anion resins. The cleaning solution, when applied via a cleaning vessel utilizing an eductor(s)/plenum and wedge-wire screen draw chamber, while controlling all phases of cleaning by electronic monitoring, yields complete restoration of ion exchange kinetics on usable resin. As such, the system and method provides a safe, effective, and vastly improved method for restoring anion resin kinetics and improving regeneration quality, for improved resin performance and minimizing resin replacement costs.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/676,128, filed Nov. 6, 2019 (published as US 20200070143, now U.S.Pat. No. 10,737,260), which is the continuation of U.S. patentapplication Ser. No. 16/292,131, filed Mar. 4, 2019 (issued as U.S. Pat.No. 10,532,351), which claims the benefit of and priority to U.S.Provisional Application No. 62/724,587, filed Aug. 29, 2018, thecontents of each of which are hereby incorporated herein by reference intheir entireties.

FIELD OF THE PRESENT INVENTION

The present invention relates to the field of cleansing and purifyingion exchange resins, and more specifically relates to a system andmethod by which resins, such as ion exchange resin, may be cleaned ofimpurities and regenerated in a expeditious and efficient manner, andkinetics of the ion exchange resin are fully restored.

BACKGROUND OF THE PRESENT INVENTION

It is known that power plants and other industries utilize ion exchangeresins to purify water used in producing steam. The rate at which ionexchange occurs at exchange sites on resin is referred to as ionexchange kinetics, and is expressed as the mass transfer coefficient(MTC), or the speed at which an exchange site on a resin bead removesionic impurities from service water through polar attraction. Excellentresin kinetics implies the resin is able to attract and removeimpurities before the water carries them past ion exchange sites, andcan be summarized as, “The better the kinetic properties are on resin,the higher the quality of effluent waters it will produce.” Organicmaterials and iron oxides adhering to the surface of resins can blockexchange sites, slowing the ability of the resin to attract and removeimpurities. Blocking exchange sites on resin surfaces results in higherlevels of impurities remaining in effluent waters.

To control corrosion rates in plant equipment, the power industryelevates the pH of process waters with various organic amines. Organicadditives chemically break down in regions of high temperatures. Theresulting decomposition products are captured on surfaces of ionexchange resins, causing the resins to become fouled.

It has recently been determined that decomposition products of pHcontrol additives such as Monoethanolamine (ETA/MEA) are captured onresins as both, positively and negatively charged anions, resulting inETA/MEA organic complexes. Current resin regeneration processes areunable to effectively remove anionic ETA, or organic and iron oxidefoulants from resin surfaces, rendering anion resins incapable ofperforming ion exchange. Degraded kinetic properties due to organicfouling, results in increased chloride, sulfate and silica slippage fromion exchangers during service runs. Impurities in industrial feedwaterschallenge chemistry goals designed to minimize corrosion. Typically,kinetically fouled resin must be removed from service, discarded, andreplaced with new. The system and method of this invention removesundesirable foulants from the surface of resins, enabling extended lifespans for resin.

Replacing resin charges is extremely costly, and if discarded resin iscontaminated with detectible isotopic activity (nuclear power) the costto bury as radwaste significantly increases replacement costs.Previously, no known acceptably safe or effective method has existed forremoving organic fouling and iron oxides from the surface of resinbeads. The system and method of this invention efficiently cleans andrestores resin ion exchange kinetics by removing all organic materials,resin surface-loaded iron oxides, resin fines, suspended iron oxides,with regenerations that provide final rinse qualities exceeding thelevels of new resins.

The increasing demands in the utility sector to lower feedwaterimpurities as a result of resin maintenance activities are welldocumented gaps in maintaining health and readiness of condensatepolishing resins. Conventional regeneration methods are unable tomaintain ion exchange kinetics on polisher resins. Uncommon innovationshave been integrated into the system and method of this invention toeffectively remove resin fines, suspended and attached iron, andorganic/organometallic materials from resins. Additionally, thisinvention facilitates removal of radioactive material from waste nuclearresins, to levels allowing release as landfill grade waste.

Few solutions to this issue can be found in prior art. For example,sodium bisulfite has been proposed as a solution for removing rust fromwater softeners, as taught by Hatch (U.S. Pat. No. 3,139,401), howeverthe solution lacks the efficacy and simplicity of the system and methodof the present invention. Other resin regeneration chemicals have beenpreviously patented for their anion/cation resin separation properties,but the scope of the application as taught by Auerswald (U.S. Pat. No.4,511,675) is limited.

SUMMARY OF THE PRESENT INVENTION

The objective of the present invention is to provide a safe, and moreefficient method to clean and regenerate resins, by restoring degradedresin ion exchange kinetics to ultimately extend the resin lifespan.

The present invention was devised to clean and restore degraded ionexchange kinetic properties of water treatment resins, by utilizing asulfite reducing solution (15) catalyzed with acid. If required, cationand anion resins are able to be separated for the cleaning evolutionutilizing a specific chemical density that is complimentary to eachseparate density of cation and anion resins. When suspended in aspecific chemical, resins will separate based on respective resindensities. Alternatively, mechanical means may be employed to separateeach of the two resin species by size or density, if the cleaningprocess so dictates. Cation and anion resins require specific regenerantchemicals, requiring isolation specific to cation or anion resin, whichmay be accomplished pre or post-cleaning. Regeneration of resins occuronly after resins have been physically and/or chemically cleaned.

The system and method of this invention employs a certain cleaning andregeneration vessel, whether vertical (45) or horizontal (50), whichutilize unique properties of a wedge-wire draw chamber (55) and acentral transfer eductor/plenum (60, 65) or similar apparatus. Fouledresins are drawn from the floor of the vessel draw chamber (55) anddelivered to the top of the resin charge using an eductor/plenum (60,65) and catalyzed reducing solution (15). High quality regenerationsfollowing the cleaning cycles, described in this invention can beperformed in a single cleaning/regeneration vessel (45)(50). Monitoringprocess chemical reactions at various locations throughout thecleaning/regeneration vessel (45)(50) provides quantitative sentience ofprocess status. High quality final regeneration rinse end-points aremade achievable through applying diffusion-shifted displacement (90)rinse techniques.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and form a partof the specification, illustrate the present invention and, togetherwith the description, further serve to explain the principles of theinvention and to enable a person skilled in the pertinent art to makeand use the invention.

The present invention will be better understood with reference to theappended drawing sheets, wherein:

FIG. 1 depicts an overview perspective of a conventional cleaning vessel(10) and cleaning vessels employed in the process and system of thepresent invention (45)(50).

FIG. 2 depicts a flow chart of major components of the cleaning process,Resin, Chemical Solutions, Process Flow, and Process Control of use ofthe method of the present invention for restoring resin kinetics.

FIG. 3 exhibits a view of Electronic Monitoring System (40) associatedwith the method and system of the present invention, depicted in use ofResin Elution Gradient (40) Profiles.

FIG. 4 shows a cross-sectional view of the Vertical Cleaning VesselLayout (45) employed in the method and system of the present invention.

FIG. 5 shows a cross-sectional view of a suggested Horizontal CleaningVessel (50) employed in the method and system of the present invention.

FIG. 6 illustrates a diffusion-shifted displacement (90) approach tofinal rinses of the method and system of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present specification discloses one or more embodiments thatincorporate the features of the invention. The disclosed embodiment(s)merely exemplify the invention. The scope of the invention is notlimited to the disclosed embodiment(s). The invention is defined by theclaims appended hereto.

References in the specification to “one embodiment,” “an embodiment,”“an example embodiment,” etc., indicate that the embodiment describedmay include a particular feature, structure, or characteristic, butevery embodiment may not necessarily include the particular feature,structure or characteristic. Moreover, such phrases are not necessarilyreferring to the same embodiment. Further, when a particular feature,structure, or characteristic is described in connection with anembodiment, it is submitted that it is within the knowledge of oneskilled in the art to effect such feature, structure, or characteristicin connection with other embodiments whether or not explicitlydescribed.

The present invention is a system and method for the purification andcleansing of resins and resin surfaces in order to restore resinkinetics (mass transfer coefficient—MTC) and ion exchange functionality.When a bisulfite solution is buffered with an acid solution to the pHrange of 3.0-5.0, anionic organic and protonated organometalliccomplexes efficaciously detach from anion resin surfaces. For thepurposes of this application, this combined solution is referred to asthe cleaning solution (15). When organic materials are removed fromresin surfaces, ion exchange functionality (kinetics) is restored,allowing resin to perform as designed. Following exposure to thecleaning solution (15), ion exchange sites are fully exhausted andrequire multiple regenerations with concentrated acid or causticsolutions to fully restore ion exchange capacities. Periodic sulfitecleanings bolster resin health initiatives and maintenance programs byeliminating cumulative negative effects of organic impairment on resins.

The method of the present invention employs at least one vessel(10)(45)(50) as disclosed in FIGS. 1-6, to facilitate the restoration ofthe kinetic properties of the resin. A primary benefit of the system andmethod of the present invention is that multiple chemical processestypically requiring use of three or more separate vessels, have beencombined into a single multi-use vessel (45)(50). This newly designedvessel (45)(50), when combined with sulfite reducing chemical, removesresin fines, suspended iron and debris, restores kinetics, regenerates,and rinses resin to specifications rarely achievable with currentlyregeneration processes. As such, the method of the present invention isaccomplished via use of a multi-use cleaning vessel (45)(50), containinga central eductor/plenum (60, 65), wedge-wire screen draw-chamber (55),sulfite/catalyst reducing solution (15), an electronic monitoring andcontrol system (40), and a diffusion-shifted displacement (90) finalrinse process.

Benefits and strengths of the present invention may include, but are notlimited to:

-   1. Noncombustible and nonflammable sulfite/catalyst reducing    chemical.-   2. Maintains chemical compatibility with rubber linings and    stainless-steel alloys.-   3. Cation complimentary as a cation bisulfite, ammonium bisulfite.-   4. Chemical reactions are monitored real-time during the cleaning,    regeneration, and rinsing process (elution gradient (40) profiling).-   5. Diffusion-shifted displacement (90) rinse techniques drive    lowered final rinse end-points.-   6. Central eductor/plenum (60, 65) drawing of resin from off the    bottom of cleaning vessel (45)(50), depositing on top of the resin    charge, when in contact with cleaning and regenerant chemicals.-   7. Continuous resin and chemical recirculation.-   8. Requires less than 10% of current processes regeneration    chemicals.-   9. Generates less than 10% of regeneration wastes of current    processes.

The eductor/plenum (60, 65) of the present invention is preferably anoff-the-shelf item which can therefore be sized and purchasedspecifically for vessel (45, 50) size. Eductor (60) sizing for totalresin volume transport capability is determined by vessel (45)(50) size,system pressures, gpm of eductor (60) motive solution, and desired totalcubic feet of resin to be drawn per unit of time. Per convention, theeductor (60) of the present invention is used to facilitate mixing andcontact time of chemical with resin and provides motive solution fordirect transfer of resin from vessel bottom to vessel top. Theeductor/plenum (60, 65) of the present invention is equipped withpotentially a variable-flare extension extending to above the upperlevel of resin. The flared extension plenum (65) of the eductor (60) isconfigured to provide a direct transfer path for depositing resin on thetop of the resin charge, from the bottom of the vessel draw chamber(55). Flow paths of the present invention includes resin drawn from offthe floor of the vessel draw chamber (55), transporting the resin &solution (15) upward through the plenum (65) to exit the plenum (65) andsettle as the top layer of resin. The main function of theeductor/plenum (60, 65) is to draw resin & solution (15) from the vesselbottom, and to provide a direct pathway to the top of the resin charge.During the transfer process, the upper layer of resin is drawn downwardthrough the vessel and into the wedge-wire draw chamber (55) until itreaches the bottom of the draw chamber. Once there, the eductor (60)draws it from the floor bottom to push it upwards through the plenum(65). Inside the eductor (60), the resin and cleaning/regenerationsolutions (15) are mixed via vortex flow motion, travelling up theplenum (65) and exiting onto the top of the resin charge. This flow pathis performed continuously until the resin is clean or requiresregeneration. Regeneration and rinse flows are identical to the path ofthe cleaning chemical.

This resin transfer and circulation process within the vessel (45)(50)of the present invention is in contrast to conventional resincleaning/regeneration vessels in which cleaning and regenerationchemicals are forced through compacted resins. Conventional regenerationmethods move chemical through a motionless resin bed. In suchcleaning/regeneration vessels, frequent issues associated with high/lowflow regions within the cleaning vessel, and flow anomalies that are aresult of various pendant transport headers designed into the vessel,require skilled troubleshooting and constant attention to the process.The use of an eductor (60) utilizing an extended discharge plenum (65)in the system of the present invention resolves issues associated withconventional regeneration vessels, such as low-flow regions, headerinduced flow anomalies, and regions of residual chemical hide-out.

A critical attribute relating to the efficacy of the system and methodof the present invention is the ability to monitor and control chemicalsand reactions on resins during all phases of the cleaning, regeneration,and rinse processes. Use of an electronic monitoring and control system(40), precisely configured within the vessel (45)(50), monitors resinand chemical reactions throughout the cleaning, regeneration, and finalrinse processes of the system.

Chemical monitoring is achieved via the use of strategically positionedconductivity/toroidal sensors (20), pH sensors, temperature sensors,sodium instrumentation and other electronic means (40), of securingprocess information. Data received from electronic sensors (20) iscollected by a data logger/integrator (30), used to develop elutiongradient (40) profiles during each step of the cleaning, regeneration,and rinse process. The data set, when displayed graphically, producesunique elution gradient (40) profiles representing conductivity, pH,concentrations, and various other chemistry constituents, per unit time.The elution Gradient (40) profile, of the electronic monitoring system(40), provides graphic representation of process data for conductingforensic analysis, and is extremely valuable when attempting tointerpret process anomalies.

Intended use of the electronic monitoring (40) data of the presentinvention is to provide insights for revising process parameters, steptimes, chemical concentrations, process termination, etc. Gradientprofiles act as baselines for comparing performance shifts, trending andpredictive analyses. Recommended strategic placement of these elementsof the electronic monitoring and control system (40) of the presentinvention can be seen in FIG. 1.

Baseline curves of the results provided by the electronic monitoring andcontrol system (40) are initially derived by processing each newlypurchased resin charge prior to being placed into service. Cleaning andregeneration data of newly purchased resin charges provides insight tobaseline data of virgin resin prior to contamination, and can be usedfor predictive trending of resin degradation over time. As such,subsequent cleaning and regeneration activities performed by the systemof the present invention on aging resins relies on baseline data(curves) and end-points as a model for anticipating and achievingcompletion of each step of the cleaning and regenerating process. Dataloggers (30) gather real-time data during each separate phase,permitting real-time and forensic evaluation of the data upon completionof the cleaning and regeneration process. This becomes very useful inthe event that programmed steps for cleaning times, flow rates, orchemical concentrations fail to clean, recover, regenerate, or rinseresins to acceptable quality as expected.

Benefits of performing an initial regeneration elution gradient (40)profile on newly purchased resins with this system and method of thepresent invention are twofold; firstly, it removes residual organicsulfonates that remain on new cation resins due to the manufacturingprocess, which is known to severely degrade anion resins; secondly, itestablishes baseline information of a newly purchased resin charge,which is used to compare future cleaning and regeneration data againstas the resin degrades with time and use. Baseline data allowsqualitative and quantitative adjustments to the cleaning andregeneration processes to account for degrading trends. Comparing futureregeneration data to the original baseline data permits the user todevelop requisite cleaning and regeneration strategies to address minorshifts in performance, before degradation is irreparable, resulting inuninhibited impurity throw. Electronic monitoring of the system (40) andmethod of the present invention arms the user with evidence of deficientparameters, such as inconsistent chemical concentrations, inadequateinjection times, or grossly extended rinse times. Modifications to theprocess can be made to make minor adjustments for maintaining ahigh-quality effluent. The ability to observe and trend minor shifts inphysical and/or chemical attrition during performance of cleaning orregenerating resins, is currently unavailable.

Output from electronic monitoring instrumentation chemistry meters (25),employed in the electronic monitoring and control system (40) of thepresent invention is configured to interface with a Programmable LogicController (PLC) (35) per convention, to provide controller feedbackfrom which the PLC (35) can respond to process parameters. The PLC (35)can adjust system pumps, valves, repeat sequences, alter step times andconcentrations, etc. during process execution. The system is preferablyconfigured to automatically make adjustments to certain predefinedparameters as required, based on feedback received from the electronicmonitoring system (40).

For example: if pH of the cleaning solution trends downward in onesection of the vessel (45)(50) from an adjacent section (as indicated bya corresponding drop in pH readouts) the system responds by adjustingfeed valves slightly more open to allow additional cleaningchemical/acid solution (15) until pH has recovered and is beingmaintained in the desired range. The PLC (35) receives output signalsfrom Toroidal (conductivity), pH, flow, Temperature, and sodiuminstrumentation (20). As the PLC (35) receives process data, it willgenerate appropriate control signals to system parameters. Built-in steptimers control times and sequences to process resins with the correctchemical concentrations to recover kinetics and ion exchange capacities.Data loggers & integrators (30) record output data (temp, conductivity,pH, dates/times, flow rates, chemical concentrations, etc.) forreal-time and forensic evaluation of the process.

The electronic monitoring and control system (40) of the presentinvention acts as a go/no-go tool during regeneration. If 16% regenerantis being injected onto resin during a regeneration, eventually the wastestream will also reach 16% concentration as the resin becomes fullyregenerated, and chemical demand has ceased. The operator can terminatethe injection step, even though additional time has been allocated andprogrammed for this step. Continuing the injection of caustic in thoseconditions results in wasted chemical, and creates unnecessary wastevolumes to neutralize and disposition. Likewise, if the waste stream ismeasuring only 10% concentration when the step time has expired, and 16%is being injected, the user would certainly extend the injection stepuntil the resin's chemical demand has been satisfied, as indicated by16% concentration of caustic in the waste stream. If resin chemicaldemand is not satisfied during the regeneration process, short run timesand potential ionic leakage can occur. Real-time data arms the user withpreviously unavailable insights that quantifiably justify operatorintervention when needed. As the data logger (30) collects and processesdata for graphic display, the PLC (35) responds to automatic feedback ofsystem parameters to actuate valves and pumps. Touch screen displayswhich are part of the PLC (35), provide operators with ahuman-machine-interface (HMI) for over-ride control when required.

Experimental Results

Ammonium sulfite monohydrate can be dissolved in water or metabisulfitecan be purchased in liquid form at desired concentrations below 70% toprepare the cleaning solution (15). Impure liquid bisulfite solutionscontaining stabilizers such as potassium hydroxide, sodium carbonate, orother commercial preservatives, exhibited impaired cleaning capabilitiesduring testing. Concentrated bisulfite solutions in the liquid form mustbe free from all manufacturing stabilizers to perform effective organicand iron removal.

The cleaning process effectively cleans resin in any state ofexhaustion. Cleaning cation and anion resins in the mixed state seemedto have no adverse impacts, although anion and cation resins must beseparated prior to post-cleaning regeneration.

For efficient resin cleaning, specific gravity/density and pH of thecleaning solution (15) must be maintained. Specific gravities of ˜1.40were required to allow exhausted cation resins to settle, and specificgravities of ˜1.10 were required to float exhausted anion resin,although different levels of organic or iron fouling contributed toadditional density of used resins. When resins became super-saturatedwith ammonia and sulfate, resin densities increased, requiringadjustments to strengthen chemical concentrations. When anion resinbecame super saturated with sulfate that was converted from sulfiteduring the cleaning process, it was noted that the resin requiredseveral cycles of cleaning and regenerations to fully remove ironcompounds that had been complexed with hydroxide during priorregenerations. If resin was severely fouled with surface iron, severalcleaning/regeneration cycles were required to remove the surface iron.Significant kinetic restoration was consistently found to occur afteronly a single cleaning cycle followed by dual regenerations, which ispositive news if ion exchange kinetics are the focus of resin cleaning.If 100% iron removal is the goal, several cleaning and regenerationcycles via use of the system and method of the present invention areneeded.

If resin is cleaned as a mixed bed, they must eventually be separated toenable individual cation and anion regenerations. Chemical byproductsthat are produced by the cleaning process include a small amount ofsulfur dioxide fumes, water, and ammonium sulfate waste. As thesulfite/catalyst solution (15) protonates iron oxides, the sulfite isconverted to sulfate, altering pH, conductivity, and density of thecleaning solution (15). Close scrutiny of system parameters is vital formaintaining proper cleaning solution (15) concentrations during thecleaning process to ensure efficiencies are maintained and organic andiron foulants are deconstructed.

Extreme care should be taken to minimize contact of ambient or othersources of free oxygen with the sulfite cleaning solution (15), asavailable oxygen will be immediately consumed by the cleaning solution(15), converting available ammonium sulfite to ammonium sulfate, anddecreasing iron reducing properties of the cleaning solution (15).

Anion resins having significant kinetic impairment due to iron, requiredadditional contact time (cleaning & regeneration cycles) withsulfite/catalyst cleaning solution (15) to remove the majority of iron.

Laboratory experiments showed that consistent ion exchange kineticrecoveries were achieved with concentrations ranging from ˜2.0%-40.0%ammonium bisulfate solutions (15), catalyzed with ˜0.5%-2.0% sulfuricacid concentrations.

Restoration of resin ion exchange capacity is required after fullyexhausting during cleaning, and requires a minimum of two regenerationsat manufacturer recommended regenerant dosages. Prior to post/cleaningregenerations, all residual cleaning solution must be thoroughly rinsedfrom the exhausted anion resins to avoid thermal damage of resinsurfaces that can result due to exothermic reactions of the low pHcleaning solution (15) and caustic regenerant.

During the testing process, a 2N sodium hydroxide regenerant solutionwas used to regenerate anion resin to full ion exchange capacity,increasing anion resin kinetics from 1.4-1.6×10E−4 m/s, to greater than2.0×10E−4 m/s (MTC). No adverse effects have been noted on resinsresulting from the present invention. Regeneration of newly purchasedresin is highly recommended prior to first use.

Referring to FIGS. 1-6, use of the process, method and system of thepresent invention is preferably as follows:

A. CHEMICAL—THE CLEANING SOLUTION (15)

-   1. Sulfite (SO3) reducer (ammonium bisulfite or similar)-   2. Acid (H2SO4) catalyst (sulfuric acid or similar)

B. RECIRCULATION EDUCTOR/PLENUM: (60, 65)

-   1. Off-the-shelf eductor (60) purchased)-   2. Extended plenum (65) (purchased/fabricated)-   3. Increased contact time (resin & chemical)-   4. Recirculation method (resin drawn from bottom & deposited on top)-   5. Complete resin ion exchange kinetics recovery (as-new condition)-   6. High quality resin regeneration (100%)

7. Extremely high quality rinse end-point (<1.0 μS)

-   8. Less than 10% of normal chemical usage (˜7%)-   9. Less than 10% of normal time to regenerate-   10. Less than 10% of normal waste stream volumes generated

C. WEDGE-WIRE DRAW-CHAMBER: (55)

-   1. Off-the-shelf, order to build, resin screen (purchased) (55)-   2. Forced resin, eductor (60) draw

D. AUTOMATED ELUTION GRADIENT PROFILE: (40)

-   1. Electronic chemical process measurement during each phase-   2. Go/no-go tool for process termination/extension-   3. Forensic evaluation of cleaning, regeneration & rinse processes

E. DIFFUSION-SHIFTED DISPLACEMENT RINSE END-POINTS: (90)

-   1. Significant rinse water & waste volume reductions-   2. Significant time reduction

F. DEVICE IDENTIFICATION REFERENCE NUMBERS

-   10 Conventional cleaning vessel-   15 Cleaning Process, including resin types, chemicals used, four    cleaning phases, electronic monitoring control system-   20 Electronic measurement probes of various nature, including pH,    conductivity/toroidal, temperature, concentration, flow rate (gpm),    etc.-   25 Chemistry meters-   30 Digital Integrator/Data Logger-   35 Programmable Logic Controller (PLC)-   40 Electronic Monitoring System—Elution Gradient Profiling (data    graphing)-   45 Vertical Cleaning Vessel-   50 Horizontal Cleaning Vessel-   55 Wedge-wire Screens Draw Chamber-   60 Eductor-   65 Plenum-   70 Chemical & Water inlet-   75 Eductor Motive Feed, Chemical/Water-   80 Waste Outlet-   85 Resin Inlet/Outlet-   90 Diffusion-Shifted Displacement

It should be understood that the singular vessel (45)(50) of the presentinvention containing, eductor(s) (60), plenum (65), wedge-wire screens(55), and electronic monitoring system (40), are to be utilized duringfines removal, entrained iron removal, kinetics recovery, and resinregeneration/rinse processes. Similarly, it should be noted that thevessel (45)(50) of the present invention, is sealed or pressurized withwater and/or cleaning solution (15) when performing ion exchangekinetics recovery steps utilizing cleaning/reducing agents composed inpart of sulfite. On contact with available free oxygen,cleaning/reducing solutions convert from sulfite to sulfate, reducingits efficacy to deconstruct long-chain organic material or iron oxides.

Post cleaning regenerations are required to reactivate ion exchangesites on resin surfaces. Final rinses can tally many thousands ofgallons and hours of rinsing to achieve rinse end-point goals, usuallyin the range of <0.080 μS, which is very close to pure water (0.055 μS).Many times, resins exhibiting fouling or impaired kinetics will neverreach desired rinse end-points or flow anomalies exist within the resinvessel (45)(50) that inhibit effective hydraulic conditions for reachinghigh quality rinse end-points. Rinse conductivities will often rinsedown to approximately 10-15 μS and then level off and refuse to rinsedown any further.

A method for achieving extremely low final rinse end-points has beendeveloped as part of the system and method of the present invention,that exploits mass transfer properties of physics to achieve excellentrinse end-point conductivities. Residual regenerant chemicals capturedinside surface crevices of resins during regenerations, will experiencedifficulty “rinsing” out of resin surface micro-crevices due tohydraulic pressures on resin surfaces associated with high-rate flowsduring fast rinses. To effectively remove these crevice contaminants,flow should be terminated. For example, short soak periods of fiveminutes or so, allows concentrated impurities held inside crevices tonaturally diffuse out of the crevice and into interstitial waterssurrounding the resin.

Natural diffusion always flows from high concentration to lowconcentration. Equilibria is reached relatively quickly as interstitialwaters become saturated to that of the surfaces inside crevices,essentially stopping the diffusion process. When contaminantconcentrations become equal between crevice surfaces, and thesurrounding interstitial waters, displace (to waste) one bed volume ofde-ionized (DI) water from the resin charge. As fresh DI water replacesthe contaminated water for another soak, the diffusion process beginsagain, moving from crevices to surrounding waters until contaminantlevels inside crevices are low enough to produce the desired final rinseend-points.

A series of soaks followed by single-bed-volume displacements have beenshown to save substantial amounts of DI water, eliminating unnecessaryhours spent rinsing. Depending on relative conductivity starting pointsof the diffusion-shifted displacements (90), each displacement may yieldup to 50% reduced contaminant levels as rinse conductivities decrease.

Soak times can be altered. After several soak steps have been performed,and crevice contamination levels have decreased, longer soak times mayyield greater impurity removal, due to weakened diffusion driving forcedue to lowered concentrations of impurities remaining inside crevices.Highly concentrated crevices quickly saturate surrounding waters,halting the diffusion process until it is replaced with fresh DI water.Typically, shorter soak times are required initially, with longer soaktimes needed towards final displacement end-point conductivities areachieved.

In short, it should be noted that the process of the present inventionusing the vessel of the present invention is preferably as follows:first, obtain spent resin. Then, the spent resin is introduced to thevessel (45, 50), the vessel contains a sulfite reducing chemicalcleaning solution (15), as well as a sulfuric acid for the regenerationof cation resins, and sodium hydroxide for the regeneration of anionresins. The cleaning solutions (15), including the regenerants as wellas flush waters are preferably configured to flow bi-directionallythorough at least one wedge-wire screen to facilitate cleaning andregeneration of the resins. Further, the resins are contained andchanneled within a wedge-wire screen draw chamber (55) as the resin ispulled towards the bottom of the vessel (45, 50) via an eductor. Thewedge-wire screen draw chamber (55) removes waste from the resin whenthe resin reaches the bottom of the vessel (45, 50). The vessel outputsthe waste removed from the resin via a waste outlet (80), a wedge-wirewaste outlet, or both. The eductor (60) is equipped with a plenum (65)which redirects the resin to the top of the vessel (45, 50) where it maybe recirculated back down towards and through the wedge-wire screen drawchamber. The electronic monitoring and control system of the presentinvention employs electronic sensors which monitor and respond to thecurrent state of the chemical(s) (cleaning solution (15)) and resin asit circulates within the vessel. After cleaning, the resin isregenerated, and then rinsed using a diffusion-shifted displacement (90)final rinse process to achieve a specific predetermined state.

Having illustrated the present invention, it should be understood thatvarious adjustments and versions might be implemented without venturingaway from the essence of the present invention. Further, it should beunderstood that the present invention is not solely limited to theinvention as described in the embodiments above, but further comprisesany and all embodiments within the scope of this application.

The foregoing descriptions of specific embodiments of the presentinvention have been presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit thepresent invention to the precise forms disclosed, and obviously manymodifications and variations are possible in light of the aboveteaching. The exemplary embodiment was chosen and described in order tobest explain the principles of the present invention and its practicalapplication, to thereby enable others skilled in the art to best utilizethe present invention and various embodiments with various modificationsas are suited to the particular use contemplated.

I claim:
 1. A cleaning system configured to clean and regenerate kineticand ion exchange properties of resin, comprising: a vessel comprising abottom, at least one solution inlet, at least one waste outlet, at leastone resin inlet, and at least one resin outlet; a draw chamber disposedinside the bottom of the vessel, the draw chamber comprising aseparation screen; at least one eductor; a plenum in fluid communicationwith the at least one eductor, discharging from the at least one eductorat a top of the vessel; a fouled/exhausted resin comprising at least oneresin, each resin of the at least one resin being one of cationic andanionic in nature; a first resin regeneration chemical flowing throughthe at least one eductor into the vessel, wherein the first resinregeneration chemical is a chemical regeneration solution for one ofcation resins and anion resins; a sulfite solution circulating throughthe at least one eductor into the vessel along with the fouled/exhaustedresin, the sulfite solution performing a reducing reaction; and whereinsaid at least one eductor are configured to recirculate resin throughoutthe vessel as the separation screen and the sulfite solution worktogether to remove at least one of organics, iron oxides, waste, anddebris from the resin.
 2. The system of claim 1, wherein the vessel isoriented vertically.
 3. The system of claim 1, wherein the at least oneresin of the fouled/exhausted resin is a used resin.
 4. The system ofclaim 1, wherein the at least one resin of the fouled/exhausted resin isnew and in need of pre-conditioning.
 5. The system of claim 1, whereinthe at least one eductor is disposed outside of the vessel, and isconfigured to draw resin from the bottom of the vessel to the top of thevessel.
 6. The system of claim 1, wherein the at least one eductor isdisposed internally to the vessel.
 7. The system of claim 1, wherein thevessel is configured to be at least one of sealed, pressurized, andfilled with at least one of water and sulfite solution, to preventintroduction of free oxygen to the vessel.
 8. The system of claim 1,wherein the sulfite solution converts to sulfate as part of a reducingreaction to clean resins prior to the introduction of the first resinregeneration chemical.
 9. The system of claim 1, wherein the sulfitesolution converts to sulfate as part of a reducing reaction to cleanresins prior to the introduction of a second resin regeneration chemicalflowing through the at least one eductor into the vessel, wherein thesecond resin regeneration chemical is a chemical regeneration solutionfor one of cation resins and anion resins.
 10. The system of claim 1,wherein the sulfite solution is catalyzed and configured to deconstructand remove organic and metal oxide materials adhered to resin surfaces.11. The system of claim 1, wherein at least one of the at least oneeductor and the plenum discharge within the vessel above the resin, andare disposed in a location that is one of internally within the vesseland externally on the vessel.
 12. The system of claim 1, furthercomprising an electronic monitoring and control system communicativelycoupled to a data integrator having real-time monitoring capabilities, aprogrammable logic controller (PLC), and at least one sensor disposed onat least one interior side of the vessel.
 13. The system of claim 12,wherein the electronic monitoring and control system is configured toprovide monitoring alerts, visual and statistical feedback that relatesto the state of the resin during cleaning via at least one displayscreen.
 14. The system of claim 12, wherein the electronic monitoringand control system comprises at least one sensor configured to monitorthe state of the fouled/exhausted resin and the first resin regenerationchemical as they recirculate within the vessel and through the at leastone eductor.
 15. The system of claim 12, wherein the electronicmonitoring and control system comprises at least one sensor configuredto monitor the state of the sulfite solution as it recirculates withinthe vessel and through the at least one eductor.
 16. The system of claim1, wherein the separation screen is a wedge-wire screen.
 17. The systemof claim 1, wherein the vessel is oriented horizontally.
 18. A method ofcleaning iron and organically fouled ion exchange resin for reuse of theresin, comprising: introducing the fouled/exhausted resin to a vesselthrough at least one eductor, the vessel containing a sulfite chemicalcleaning solution configured to perform a reducing reaction to cleanresins prior to regeneration, converting the cleaning solution tosulfate; circulating the cleaning solution, the regeneration chemical,and rinse waters to flow bi-directionally through at least oneseparation screen of a draw chamber as the resin is moving about thedraw chamber as it is pulled towards a bottom of the draw chamber by theat least one eductor; separating waste from the resin using the at leastone separation screen of the draw chamber; recirculating the resin fromthe bottom of the separation screen draw chamber to the top of thevessel using the at least one eductor and a plenum in fluidcommunication with the eductor, where the resin travels downward againinto the separation screen draw chamber; catalyzing the sulfite chemicalcleaning solution to form a reducing solution to deconstruct and removeorganic and metal oxide materials adhered to resin surfaces within thevessel, as a cleaning phase; introducing to the vessel through the atleast one eductor a first resin regeneration chemical to regenerateresins for re-use as part of a regeneration phase, the regenerationphase occurring after the cleaning phase; and rinsing the resinutilizing a diffusion displacement final rinse process once the resinobtains a specific predetermined state.
 19. The method of claim 18,wherein the determination that the resin has obtained the specificpredetermined state is made by an electronic monitoring and controlsystem comprising a plurality of sensors to monitor the state of theresin as it recirculates within the vessel.
 20. The method of claim 18,further comprising: separating the fouled/exhausted resin into an anionresin and a cation resin during the cleaning phase and before theregeneration phase; and introducing to the vessel through the at leastone eductor a second resin regeneration chemical to regenerate resinsfor re-use as part of the regeneration phase; wherein the first resinregeneration chemical is a chemical regeneration solution for cationresins; wherein the second resin regeneration chemical is a chemicalregeneration solution for anion resins.